Many different types of forms or the like are conventionally printed upon a continuous web of paper having lateral perforations for subsequent separation of the individual forms. Invoices, records, checks, computer readouts and many other types of printed forms and records are conventionally formed in the foregoing manner, at least in parts to increase the available speed of printing and ease of handling. Separation of the individual forms or pages from the continuous web or strip of stationery is commonly accomplished by means of a "burster" which pulls apart successive sheets along the perforation lines of the web.
Conventional bursters employ a pair of feed rollers which grip a web of paper and feed the web forwardly into a pair of contacting snap rollers which are driven at a rate of rotation greater than the feed rollers, so as to grip and jerk or yank the end of the web, and the pairs of rollers are separated so that one perforation line across the web will be disposed therebetween. In order to ensure separation of the web along perforation lines, there are commonly provided a plurality of knobs or the like, which are disposed between the pairs of rollers and over which the web is passed, with these knobs being located at the desired separation line across the web. It is also known to employ a guillotine type of device for cutting portions from a continuous web of stationery, however, the present invention relates to the previously-noted type in which the leading portion of a web is separated by bursting the perforations laterally thereacross.
As the term "burster" indicates, conventional machines of this type simultaneously part the small connection portions of the paper between perforations, and while this type of separation is generally satisfactory, the bursting action causes a substantial noise emission. The simultaneous parting of a substantial number of small pieces of paper between perforations unavoidably produces a substantial noise, and with high speed operation as is generally required, the resultant noise level often becomes quite objectionable. High speed burster operation may, in fact, be hazardous to health of human ears, as determined by Government regulations.
At least certain types of conventional bursters suffer from an additional problem of intermittently tearing or gouging edges of separated sheets along the perforation lines. This difficulty arises from intermittent misalignment of perforation lines with separating knobs or breaking rolls, and, of course, this is highly disadvantageous inasmuch as certain separated sheets may thus become unuseable.
The present invention comprises an improvement upon conventional bursters by the provision of an improved breaking element or surface which causes an entirely different type of separation along perforation lines, and which accommodates misalignment of the perforation lines with the primary breaking surface.